I don't really use the web interface; I pretty much exclusively browse through Blorp and, previously, Connect. However, from what another user told me, it's not supported on at least the default web front end. My condolences!

If you decide to switch to mobile, on Blorp you do it from the user profile; in Connect you can do it directly from any comment a user made. I imagine many other clients are similar.

If you do go that route, note that tags are entirely client side. Connect supports exporting your tags (and other settings) but only to other Connect installations (like if you switched phones or something). AFAIK Blorp does not have an export function. I cannot speak for other clients.